The agency in charge of flood control in Ho Chi Minh City has left people stunned by providing a new definition on how and when a street should be considered inundated following a heavy rain.

Thirty-two streets across the southern metropolis were submerged in water in the wake of a torrential rain on the evening of May 19, but the anti-flood agency, managed by the municipal transport department, believed not all of them should be considered ‘flooded.’

In a report released on Tuesday, the agency said that only ten of those 32 streets were actually ‘inundated’ while the others simply ‘accumulated water,’ as far as technical details were concerned.

Do Tan Long, an official from the agency, said that criteria used by the Ho Chi Minh City Department of Transport to decide whether a street is flooded or not come from the Ministry of Construction.

By this definition, a road is only 'legitimately' considered ‘inundated’ if it remains covered by no less than 0.1 meter of water half an hour after a rain ends.

All the other cases fall into the category of ‘water-accumulating,' not in any way flooding.

After the May 19 rain, Long said, only ten streets were left 0.1 to 0.25 meters deep in water, most of which had rainwater recede between 30 minutes and three hours, with some taking five hours to subside.

On the 22 ‘water-accumulating’ streets, water levels dropped after ten to 20 minutes, according to figures from the transport department.

The reality was that people had to suffer greatly from the downpour even on those streets classified as ‘not flooded’ as per the anti-flood agency’s definition.

People walk their motorcycles along submerged Ho Hoc Lam Street in Ho Chi Minh City, on May 19, 2018. This street was not considered 'flooded' by Ho Chi Minh City's anti-flood agency. Photo: Tuoi Tre